Cutting machine, especially a circular saw

Abstract

A cutting machine includes a cutting element for cutting material, a motor for driving the cutting element to rotate and a housing for containing the motor. The motor includes a rotor sleeve being formed with a receiving chamber, a motor shaft being capable of rotating together with the rotor sleeve, a stator core at least partially contained in the receiving chamber, stator coils wound around the stator core, and a stator bracket for fixing the stator core. The stator core is formed with a through hole for the motor shaft to pass there through, the stator coils are located outside the through hole and, the motor shaft is capable of rotating relative to the stator core.

What is claimed is: 
     
       1. A cutting machine, comprising:
 a cutting element for cutting a material; 
 a motor for driving the cutting element to rotate; and 
 a housing for containing the motor, 
 wherein the motor comprises:
 a rotor sleeve formed with a receiving chamber; 
 a motor shaft capable of rotating together with the rotor sleeve; 
 a stator core at least partially contained in the receiving chamber; 
 stator coils wound around the stator core; and 
 a stator bracket for fixing the stator core, and 
 
 wherein the stator core is formed with a through hole for the motor shaft to pass there through, the stator coils are located outside the through hole, and the motor shaft is capable of rotating relative to the stator core. 
 
     
     
       2. The cutting machine of  claim 1 , wherein when the cutting machine is unloaded, a ratio between number of turns per minute of the motor shaft and a rotation radius of the cutting element is in a range that greater than or equal to 100 mm −1  and less than or equal to 250 mm −1 . 
     
     
       3. The cutting machine of  claim 2 , wherein a ratio between two rotation speeds of the motor shaft and the cutting element is in a range that greater than or equal to 2 and less than or equal to 3. 
     
     
       4. The cutting machine of  claim 1 , wherein when the cutting machine is unloaded, a ratio between number of turns per minute of the cutting element and a rotation radius of the cutting element is in a range that greater than or equal to 45 mm −1  and less than or equal to 90 mm −1 . 
     
     
       5. The cutting machine of  claim 1 , wherein a maximum output torque of the cutting element is in a range that is greater than 0.6 Nm and less than or equal to 1.2 Nm. 
     
     
       6. A circular saw, comprising:
 a saw blade for cutting a material; 
 a motor for driving the saw blade to rotate; and 
 a housing for containing the motor, 
 wherein the motor comprises:
 a rotor sleeve formed with a receiving chamber; 
 a motor shaft capable of rotating together with the rotor sleeve; 
 a stator core at least partially contained in the receiving chamber; 
 stator coils wound around the stator core; and 
 a stator bracket for fixing the stator core, and 
 
 wherein the stator core is formed with a through hole for the motor shaft to pass there through, the stator coils are located outside the through hole, and the motor shaft is capable of rotating relative to the stator core. 
 
     
     
       7. The circular saw of  claim 6 , wherein when the circular saw is unloaded, a ratio between number of turns per minute of the motor shaft and a rotation radius of the saw blade is in a range that greater than or equal to 100 mm −1  and less than or equal to 250 mm −1 . 
     
     
       8. The circular saw of  claim 7 , wherein a ratio between two rotation speeds of the motor shaft and the saw blade is in a range that greater than or equal to 2 and less than or equal to 3. 
     
     
       9. The circular saw of  claim 6 , wherein when the circular saw is unloaded, a ratio between number of turns per minute of the motor shaft and a rotation radius of the saw blade is in a range that greater than or equal to 45 mm −1  and less than or equal to 90 mm −1 . 
     
     
       10. The circular saw of  claim 6 , wherein a maximum output torque of the circular saw is in a range that is greater than 0.6 Nm and less than or equal to 1.2 Nm.